With the rapid development of a wireless communications network, various data services are continuously flooding into the wireless communications network by means of the internet. After a bit rate adaptation technology is transplanted from the internet to the wireless communications network, a terminal still performs signal detection, and determines a parameter of requested data according to a detection result. After receiving a data request message of the terminal, a network side provides data for the terminal according to the parameter determined by the terminal. For example, when the terminal requests a video service from the network side, the terminal determines a bit rate of a requested video according to detected signal strength of a cell. When detecting that the signal strength of the cell is relatively strong, the terminal requests a high-definition video, and after receiving a request message of the terminal, the network side provides the high-definition video for the terminal; or when detecting that the signal strength of the cell is relatively weak, the terminal requests a standard-definition video, and after receiving a request message of the terminal, the network side provides the standard-definition video for the terminal.
Compared with the internet, a communication environment of a wireless communications network changes frequently and sharply. For this reason, a terminal cannot obtain a change of a wireless network environment in real time. Therefore, an existing method for processing a data request message of a terminal by a network side is not appropriate for a wireless communications network. For example, the wireless communications network suddenly enters a critical state of congestion, but the terminal does not obtain this in time; therefore, when a high-definition video is requested, a network layer still provides the high-definition video for the terminal, which is undoubtedly easy to cause congestion of the wireless communications network.